A device of this type is generally known from US 2002/0186871 A1 and from the field of three-dimensional angiocardiography. Three-dimensional structure data of the moving heart is obtained in rotation angiocardiography, in which an X-ray source and an X-ray detector rotates about the patient at an angular range greater than 180° and thus records projection images of the moving heart. The structure data of the object can then essentially be determined in the form of three dimensional spacial coordinates from the projection images.